Latch mechanism for levers



Get. 26, 1954 cRlPE ET AL LATCH MECHANISM FOR LEVERS 3 Sheets-Sheet 1 Filed June 30, 1952 In-Lil I 6 7w wn w mm wbHdmw N f M M T H G wm Oct. 26, 1954 G, cRlPE ET AL LATCH MECHANISM FOR LEVERS 3 Sheets-Sheet 2 Filed June 30, 1952 BY THE/f? HTTOPNEYJS. HHRAAS, K/ECH, FOSTER & HARP/s 5v Oct. 26, 1954 G. cRlPE ET AL 2,692,749

LATCH MECHANISM FOR LEVERS Filed June 30, 1952 3 Sheets-Sheet 3 /N va/vro/z's.

33 GENE H. CR/PL a5 R/c/m/w u.P5T1:es/v

BY THE]? HTTOKNEYKS. [Zn/eels, KMECH, FOSTER 6: HfiR/F/S Patented Oct. 26, 1954 UNITED STATES OFFICE 2,692,749 LATCH MECHANISM FOR LEVERS Application June 30, 1952, Serial No. 296,473

Claims.

The present invention relates to a latch mechanism for latching a pivoted member or structure in a predetermined position, the pivoted member or structure being referred to as a lever hereinafter for convenience. The lever is pivotable between a retracted position and an extended position and is adapted to be latched in the extended position by the latch mechanism of the invention, the objects of the invention including the provision of a latch mechanism which automatically latches the lever in its extended position in response to movement of the lever into such posi-' tion, and which is readily and automatically releasable to permit the return of the lever to its retracted position.

The latch mechanism of the invention finds particular utility when employed in conjunction with a shelf Which is pivotally mounted, and the invention will be considered herein in connection with a shelf which is pivotally mounted on the backrail of a cookstove, the shelf being pivotable between a lowered, retracted position and a raised, extended position wherein it is disposed horizontally to receive articles which may be placed thereon by a housewife. However, it will be understood that the invention is susceptible of applications other than the one elected for consideration herein.

Various features of the backrail disclosed herein are disclosed and claimed in our copending application Serial No. 296,472, filed June 30, 1952, reference to which is hereby made.

Considering the invention in more detail, the shelf is mounted on at least one lever with which the latch mechanism of the invention is associated. However, the shelf may be carried by two or more levers, in which case each lever has the latch mechanism of the invention associated therewith.

A primary object of the invention is to provide a pivoted lever which cooperates with a pivoted latch to latch the lever in an extended position. More particularly, an object of the invention is to provide interengaging latch means on the lever and the latch for latching the lever in the extended position automatically in response to movement of the lever from the retracted position thereof to the extended position thereof. Still another object is to provide interengaging cam means on the lever and the latch for pivoting the latch to an inoperative position so as to disengage the interengaging latch means when it is desired to return the lever to its retracted position, the interengaging cam means producing movement of the latch into its inoperative position in response to movement of the lever to a position beyond its extended position.

Another object is to provide resilient means engaging the latch for biasing it toward its operative position, and to provide locking means for releasably locking the latch in its inoperative position when the latch has been moved to its inoperative position in response to movement of the lever to a position beyond its extended position. A related object is to provide interengaging cam means on the latch and the lever for releasing the locking means during movement of the lever from its extended position to its retracted position, whereupon the biasing means restores the latch to its operative position in preparation for subsequent extension of the lever.

Another object is to provide a latch mechanism wherein the interengaging latch means on the lever and the latch are brought into engagement by momentarily moving the latch into a tripped positionwhich is intermediate the operative and inoperative positions of the latch, the latch mechanism including interengaging cam means on the lever and the latch for automatically moving the latch into its tripped position in opposition to the action of the biasing means and in response to movement of the lever from its retracted position to its extended position.

Another object is to provide a latch mechanism wherein thebiasing means is provided by one arm of a U-shaped spring and wherein the locking means includes a locking element which is insertable into a notch in the latch and which is carried by the other arm of the U-shaped spring.

The foregoing objects and advantages of the present invention, together with various other objects and advantages thereof which will become apparent, may be attained with the exemplary embodiment of the invention which is illustrated in the accompanying drawings and which is described in detail hereinafter. Referring to the drawings:

Fig. 1 is a perspective view of a cookstove hav ing a backrail on which is mounted a shelf controlled by the latch mechanism of the invention;

Fig. 2 is a rear view of the backrail showing elements of the latch mechanism of the invention, Fig. 2 being partially in section and being taken along the arrowed line 22 of Fig. 4;

Fig. 3 is a sectional view on an enlarged scale which is taken as indicated by the arrowed line 3-3 of Fig. 1; and

Figs. 4, 5 and 6 are sectional views similar to Fig. 3, but showing difierent operating positions for various elements of the latch mechanism of the invention.

Referring to Fig. l of the drawings, illustrated therein is a cookstove ll! having a horizontal cooking surface II and a backrail l2 along the rear edge of the cooking surface. Mounted on the backrail i2 is a shelf or shelf structure I3 which includes a supporting surface l4 carried by pivoted arms or levers I5, the latter extending into the backrail through slots l6. Associated with the respective levers l5 are latch mechanisms ll, Fig. 2, for latching the shelf l3 in an upper, extended position. The extended position of the shelf I3 is shown in Figs. 1 and 4 of the drawings, and the shelf is pivotable downwardly into a lower, retracted position, which is shown in Fig. 3 of the drawings. The two latch mechanisms ll are identical and only one of them will be considered in detail.

Referring to Figs. 3 to 6 of the drawings, the latch mechanism l'i illustrated therein includes elements of one of the levers 15, this lever being pivotally mounted on a frame 26 by means of a pin 2! which provides a first pivot axis, the frame 29 being secured to the backrail [2 in any suitable manner. The lever [5 includes a first latch element 22 located on one side of the pivot axis 2!, and includes first and second cam elements 23 and 24 respectively located on opposite sides of the pivot axis H, the cam element 23 being located on the same side of the pivot axis 2| as the latch element 22.

Pivotally mounted on the frame 29 by means of a pin 28 is a latch 29, the pin 26 providing a second pivot axis which is parallel to and spaced from the first pivot axis 2 l. The latch 29 is movable between an operative position, which is shown in Figs. 3 and 4, and an inoperative position, which is shown in Figs. 5 and 6. Intermediate the operative and inoperative positions of the latch 29 is a tripped position which will be considered hereinafter, this position not being shown in the drawings. The latch mechanism ll includes means 30 for biasing the latch 29 toward its operative position, and includes means 3! for releasably locking the latch in its inoperative position. The biasing means 3|] takes the form of one arm 32 of a U-shaped leaf spring 33 which is mounted on the frame 29-, as by being bolted to a tab 34 of the frame. In the particular construction illustrated, the U-shaped leaf spring 33 is compressed between the tab 34 and a tab 35 of the frame. As will be apparent, this results in the application of a spring force to the latch 29 which tends to rotate it in the clockwise direction into its operative position, the free end of the arm 32 of the spring 33 bearing against one edge of the latch 29 to bias it toward its operative position. Movement of the latch 29 beyond its operative position under the influence of the spring arm 32 is prevented by engagement of a lug 36 on the latch with a lug 31 on the frame 20, as shown in Figs. 3 and 4.

The locking means 3| includes the other arm, 4|, of the U-shaped leaf spring 33, the spring arm 4! carrying a locking element, preferably a roller 42, which is insertable into a notch 43 in one edge of the latch 29, as shown in Figs. 5 and 6 of the drawings. Thus, thev U-shaped leaf spring 33 provides elements of both the biasing means 39 and the locking means 3|, which is an important feature.

Considering the latch 29 in more detail, it includes a second latch element 46 located on one side of the pivot axis 28 of the latch and engageable by the first latch element 22 on the lever [5 to latch the lever in its extended position. On the same side of the pivot axis 29 as the latch element 46 are third and fourth cam elements 47 and 48 both engageable by the first cam element 23. As will be described, engagement of the first cam element 23 with the third cam element 4'! results in momentary movement of the latch 29 into its tripped position to permit engagement of the first and second latch elements 22 and 46, and engagement of the first cam element 23 with the fourth cam element 48 results in movement of the latch 29 into its inoperative position, in which it is releasably held by the locking means 3!. On the opposite side of the pivot axis 28 from the second latch element 46 and the third and fourth cam elements 4'! and 48 is a fifth cam element 49 which is engageable by the second cam element 24 on the lever I5 to release the locking means 3| so that the biasing means 36 may return the latch 29 to its operative position. As best shown in Fig. 2,, the third, fourth and fifth cam elements 41, 4B, and 49 comprise tabs bent laterally from the body of the latch 29, and the second latch element 46 comprises one end of the tab defining the thirdcam element 41, the first latch element 22 being adapted to engage one end of such tab.

Considering the operation of the latch mechanism l1 illustrated in Figs. 3 to 6 of the drawings, it will be assumed that the lever i5 is in its retracted position and that the latch 29 is in its operative position, which is the situation illustrated in Fig. 3. In order to move the lever [5 to its extended position, it is merely necessary to swing the shelf l3 upwardly into the position shown in Fig. 4; During the movement of the lever l5 from its retracted position to its extended position, the first cam element 23 on the'lever momentarily engages the third cam element 41 on the latch to move the latch to its tripped position, thereby permitting movement of the first latch element 22 past the second latch element 46. As soon as the first cam element 23 disengages the third cam element 41, the biasing means 36 restores the latch 29 to its operative position so that the first latch element 22 may engage the second latch element 46 to latch the lever I5 in its extended position. In other words, the first latch element 22 engages the end of the tab defining the second latch element 46 and the third cam element 41. This situation is shown in Fig. 4 of the drawings. The lever IE will remain in its extended position to maintain the shelf 13 extended until such time as it is desired to lower the shelf into its retracted position.

Referring to Fig. 5 of the drawings, whenever it is desired to lower the shelf l3, it is merely necessary to move it upwardly to a position slightly above or beyond the extended position. Such movement of the lever i5 beyond its extended position results in engagement of the first cam element 23 with the fourth cam element 43 to move the latch 29 into its inoperative position, the latch being held in this position by the releasable lockin means 3!, as shown in Fig. 5. As will be apparent, movement of the latch 29 into its inoperative position results in disengagement and separation of the first and second latch elements 22 and 46 so that the lever is may be swung downwardly into a position approaching its retracted position, as shown in Fig. 6 of the drawings. When the lever l5 reaches the p sition shown in Fig. 6, the second cam element 24 on the lever engages the fifth cam element 49 on the latch to release the locking means 3|, whereupon th biasing means 30 moves the latch 29 into its operative position again. Such movement of the latch 29 into its operative position also permits movement of the lever I5 into its retracted position. This situation is shown in Fig. 3 of the drawings.

The present invention enables the user to raise and lower the shelf I 3 with one hand and by gripping the shelf at any point, which ar important features.

Thus, the present invention provides a latch mechanism ll which automatically latches the lever H5 in its extended position as the lever is moved from its retracted position to its extended position. Also, the lever may be released readily merely by moving it upwardly beyond its extended position slightly so as to move the latch 29 to its inoperative position, the latch being restored to its operative position upon movement of the lever l5 into its retracted position.

Another feature of the invention is that, except for the free ends of the levers I5, all of the elements of the latch mechanisms ll are housed in "the backrail IE to avoid accumulations of dirt, dust, grease, and the like, thereon.

While we save disclosed an exemplary embodiment of the invention and have considered a specific application of this embodiment to a stove shelf, it will be understood that various other applications of the embodiment disclosed are possible and that various changes, modifications and substitutions may be incorporated in the embodiment disclosed, all Without departing from the spirit of the invention.

We claim as our invention:

1. In a latch mechanism, the combination of: a frame; a lever pivotally mounted on said frame for movement between retracted and extended positions; a latch pivotally mounted on said frame, the pivot axis of said latch being spaced from the pivot axis of said lever; interengaging latch means on said lever and said latch for latching said lever in said extended position in response to movement of said lever from said retracted position to said extended position; and interengaging cam means on said lever and said latch for pivoting said latch to disengage said interengaging latch means in response to movement of said lever beyond said extended position, whereby to permit movement of said lever back to said retracted position.

2. A latch mechanism according to claim 1 wherein said interengaging cam means pivot said latch into an inoperative position, said latch mechanism including means carried by said frame for releasably locking said latch in said inoperative position.

3. In a latch mechanism, the combination of: a frame; a lever pivotally mounted on said frame for movement between retracted and extended positions; a latch pivotally mounted on said frame for movement between operative and inoperative positions through an intermediate, tripped position; means engaging said latch and carried by said frame for biasing said latch toward said operative position; releasable means engageable with said latch and carried by said frame for lockin said latch in said inoperative position; first interengaging cam means on said lever and said latch for momentarily moving said latch into said tripped position as said lever is moved from said retracted position to said extended position, said biasing means thereafter restoring said latch to said operative position; inter- 6 engaging latch means on said lever and said latch for latching said lever in said extended position upon restoration of said latch to said operative position by said biasing means subsequent to said momentary movement of said latch into said tripped position; second interengaging cam means on said lever and saidlatch for moving said latch into said inoperative position upon movement of said 'lever beyond said extended position so as to disengage said interengaging latch means, said locking means releasably look-- ing said latch in said inoperative position; and third interengaging cam means on said lever and said latch for releasing said locking means as said lever is moved toward said retracted position, whereby said biasing means again restores said latch to said operative position.

4. A latch mechanism according to claim 3 wherein said interengaging latch means comprises a pair of latch elements respectively carried by said latch and said lever and wherein each of said interengagingcam means comprises a pair of cam elements respectively carried by said latch and said lever.

5. A latch mechanism according to claim 3 wherein said locking means comprises a notch in said latch and a spring-biased locking element insertable into said notch.

6. In a latch mechanism, the combination of a frame; a lever pivotally mounted on said frame for pivotal movement about a first axis between extended and retracted positions, said lever having a first latch element thereon and having first and second cam elements thereon respectively located on opposite sides of said first axis, said first latch element being on the same side of said first axis as said first cam element; a latch pivotally mounted on said frame for pivotal movement about a second axis between operative and inoperative positions through an intermediate, tripped position, said second axis being parallel to and spaced from said first axis, said latch having a second latch element thereon which is engageable by said first latch. element to latch said lever in said extended position, said latch having third and fourth cam elements thereon which are located on one side of said second axis and on the same side thereof as said second latch element, said third cam element being engageable by said first cam element upon movement of said lever from said retracted position to said extended position to move said latch from said operative position to said tripped position, said first cam element being engageable with said fourth cam element in response to movement of said lever beyond said extended position to move said latch from said operative position to said inoperative position, said latch also having thereon a fifth cam element which is located on the opposite side of said second axis from said third and fourth cam elements, said fifth cam element being engageable by said second cam element in response to movement of said lever from said extended position toward said retracted position to move said latch from said inoperative position to said operative position; means engaging said latch and carried by said frame for biasing said latch toward said operative position; and means engageable with said latch and. carried by said frame for releasably locking said latch in said inoperative position, said locking means being releasable by engagement of said second cam element with said fifth cam element.

7. A latch mechanism according to claim 6 where n said osking m ans inc u s a notch in aid lat h and a springased l n e em carried by said frame and insertable into said no ch.-

8. A latch mechanism according to claim 6 including a U-shaped leaf spring carried by said frame, one arm of said spring engaging said latch and comprising said biasing means, and the other arm of said spring carrying a locking element which is insertable into a notch in said latch and cooperates therewith to define said locking means.

9. In a latch mechanism, the combination of: a frame; a lever pivotally mounted on said frame for movement between retracted and extended positions; a latch pivotally mounted on said frame for movement between operative and inoperative positions; resilient means carried by said frame and engaging said latch for biasing said latch toward said operative position; locking means carried by said frame and engageable with said latch for releasably locking said latch in said inoperative position; interengaging latch means on said lever and said latch for latching said lever in said extended position in response to movement of said lever from said retracted position to said extended position; interengaging cam means on said lever and said latch for moving said latch to said inoperative position to disengage said interengaging latch means in response to movement of said lever beyond said extended position, whereby to permit movement of said lever back to said retracted position; and interengaging cam means on said lever and said latch for releasing said locking means to permit said biasing means to move said latch back to said operative position in response to movement of said lever from said extended position to said retracted position.

10. In combination: the latch mechanism defined in claim 1; and a housing enclosing all of the elements defined in claim 1 except a free end of said lever, which projects outwardly through a slot in said housing.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,214,018 Vleeschouwer Jan. 30, 1917 1,755,392 Hagstrom Apr. 22, 1930 2,602,442 Graham July 8, 1952 

